REPRODUCTIVE SYSTEM IN THE SNAIL. 57 



represent the result of information obtained by dissecting twenty- 

 six individuals, several of which were variously prepared and in- 

 jected with colored solutions, and of sectioning various parts of 

 the entire system of others. In view of individual variations and 

 for the sake of clarity many of the convolutions were omitted in 

 Fig. i. This is especially true in the case of the hermaphrodite 

 duct and convoluted uterus (CU) ; however, with these exceptions, 

 and that of the copulatory organ, all structures were outlined with 

 projecting apparatus. 



DESCRIPTION. 



The reproductive system of L. s. apprcssa, like that of most of 

 the hermaphroditic pond snails, comprises three major divisions : 

 (a) the hermaphrodite apparatus which includes the ovotestis and 

 hermaphrodite duct; (b) a female part including the oviduct 

 proper, the uterus with its convoluted part, albumen gland, egg 

 membrane gland and egg mass membrane gland, the vagina with 

 which the duct of the sperm receptacle is confluent and the sperm 

 receptacle and (c) the male part including the vas efferens, pros- 

 tate gland, vas deferens and copulatory organ. The male and 

 female parts of the reproductive system are quite distinct mor- 

 phologically and histologically, yet they are intricately appressed 

 and entwined except for the distal half of the vas deferens and 

 the copulatory organ. Functionally, they are similar inasmuch as 

 it is apparent that both ova and sperms may pass out either the 

 male or the female part. 



The hermaphrodite gland or ovotestis is a complexly branched, 

 more nearly digitate than acinous, gland, imbedded in the tissue 

 of the liver, though not entirely surrounded by it. Its long axis 

 conforms to that of the liver and sends irregular lobes toward the 

 convex sides of this organ or quite to its periphery (HG). The 

 apical end of the ovotestis lies within the mid-region of the third 

 whorj of the shell (C), and part of its surface is normally ex- 

 posed on the concave side, due to its not being covered entirely 

 by liver tissue in this region. Incidentally, there is no hepatic 

 tissue in the apex of the liver beyond the region marked C in Fig. 

 i, nor in certain other areas, chiefly peripheral. Baudelot ('63) 

 describes the form of the ovotestis in L. staynalis as being nearly 

 like that of an elongated triangle and F. C. Baker ('n) figures 



